Gas producer



June 26, 1934. I J w Ms 1,964,614

GAS PRODUCER Filed May 13, 1933 2 Sheets-Sheet 1 %0141I042 M27411. A

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June 26, 1934. N WILLIAMS 1,964,614

GAS PRODUCER Filed May 13, 1933 2 Sheets-Sheet 2 %n fiat/new: warn; 5) 11/5 Annie/mi WW1).

Patented June 26 1934 GAS PRODUCER John Norman Williams, London, England Application May 13, 1933, Serial No. 670,835 In Great Britain May 28, 1932 9 Claims. (01.126-182) This invention relates to gas producers of the kind in which control of the combustion'is obtained by sub-division of the grate into sections and by restricting the air supply to each section at 'a point away from the grate surface;

A grate of the kind referred to is described in the specification filed with application No. 465,966 filed July 7, 1930.

One object of the invention is an improved 'constructional form of grate.

Another object of the invention is further to improve the degree of control obtained.

According to one feature of the. invention the gas producer is characterized in that the air which at one end are relatively large to form the apertures at the grate surface, and which at apoint in their length away from such end .are relatively narrow and restricted.

According to another feature of the invention,

the ratio of the area of the restriction to the area of the aperture which it supplies is reduced to at. least one to one hundred.

Further features of the invention are embodied in the following description of a gas producer made in accordance therewith, and as illustrated in the accompanying drawings in which:

Fig. 1 is a part sectional elevation through'thecenter of the gas producer. Fig. 2 is an inverted plan of one of the conical rings forming the grate.

Fig. 3 is a section on line 33 of Fig. 2. Fig. 4 is a section on line 4-4 of Fig. 2. Fig. 5 is a plan of the scraper shown in Fig. 1. Fig. 6 is an inverted plan of the cap for the scraper. r

7 As illustrated, the gas producer will be seen to consist of a cylindrical combustion chamber ...,.a having an outermetal shell a and rings a 'of fire-proof lining, increasing in diametertowards the lower end of the chamber. The top of the chamber is closed by a metal cover a in which is mounted a feeding hopper b having a lid b arranged on a pivot 22 and having a bell "0 suspended by a chain c from the inner end of a counter-weighted lever 0 At the upper end of the chamber is a gas outlet pipe d and secured to the cover a is a baflie a to prevent material from the hopper from entering the gas outlet. In the lining of the combustion chamber are a number of poke holes e and projecting into these are tubes e secured in the shell (1 and having covers e The combustion chamber is supported by brackets'f secured to the shell (1 and mounted on pillars f combustion chamber consists of a water-cooled ring y in which are provided poke holes g anda clinker door'y The inner wall 9' of is fed to the grate surface through passages The lower part ofthe wall of the' the water-cooled ring extends below the water jacket and is slightly bell-mouthed.

Below the combustion chamber is a rotary grate consisting of a water trough h having a track h by which it is supported on rollers h each of the latter being mounted in a bracket n on a pedestal n Secured to the troughh, which will be built up of segments, are segments 71 of a worm wheel and on the foundation adjacent to the trough is mounted the worm hfi by which the whole grate may be slowly rotated. The grate proper consists of a vertical cylindrical portion 2' secured to the inner edge of the trough and on top of which is built an assembly of conical rings i 1' 2' 1' and i laid on top of each other and overlapping. The upper ring 2' is formed with a flat top and a depending tubular extension 7 to which is secured a sealing tube 7' the lower end of which reaches down into a water seal trough. To the inner edge of the water trough h is a cone is having a depending cylindrical sealing extension k Below the grate proper is a water-sealing, ashcollecting and air-supplying member I having three annular channels Z Z and Z and a central hole. This member is stationary and is positioned so that the extension k dips into the channel l in which water is kept to provide a seal, the inner edge of the cone is overhangs so as to deliver ash falling from the grate .into the channel I and the tube 7' depends into water in the channel 2 Connected to the channel Z is a vertical air pipe Z leading down into a Water seal sump m, to a branch of which pipe is connected the air inlet pipe m having an air control cowl m and a hand blower m Connected to the ring 2' of the grate and depending into the channel Z is a dust plough 11. adapted to carry round dust collected inthe channel so that it falls through the pipe 1 into the sump m from which it can be removed by a rake.

Over the grate is arranged a water-cooled scraper having two arms 0 and a central hub 0 on top of which is mounted a water-cooled cap 0 This cap may with some fuels be smaller than herein illustrated. The scraper is carried on a tubular shaft as passing through the inner ring 1' and through the central hole in the member Z, and supported at its lower end which is square, in a socket 0 The water-coolingspace of the arms is open to the tubular member through av central hole through which passes a' central water inlet pipe 0 reaching to the top of the Watercooled cap 0 Aconnection to the pipe 0 is taken through the shaft p below the member I and an outlet pipe connection is also provided below the member Z and communicating with the interior of the shaft. Theunderside of the hub 0 covers the joint of the shaft 10 in thering i and the un de'r-side of the arms 0 are stepped to correspond with the stepsof the conical grate. The shaft 10 intermediate rings.

is arranged to allow the scraper to rise if required, and lever mechanism, embodying a weighted lever 11 is provided for adjusting the effective weight of the scraper against being lifted by any obstruction adhering to the grate. The lever p which is located adjacent the lower end of the hollow vertical shaft p is disposed approximately horizontally and it extends outwardy from the central portion of the gas producer. The lever p is fulcrumed at its inner end at the central portion of the gas producer and it is connected intermediate of its ends with the vertical shaft p and it is provided at its outer portion with a weight arrangedto urge the vertical shaft 10 downwardly. The weight is adjustable along the outer portion of the lever for varying the pressure exerted in a downward direction by the lever on the vertical shaft and the scraper carried by the upper end of the shaft 10. By adjusting the, weight of the lever p the desired pressure of the scraper on the grate may be obtained.

As will be seen, the whole of the air supply for the grate surface is taken through the watersealed chamber below the rings of the grate, the

g h construction of which rings forms the air supply grate apertures and the restricted inlets thereto in the following manner. On the underside of the conical rings 2' 1' 2' and i are a series of bosses q which rest upon the upper surface of the ring below and have tapered spaces r between them which form tapered air passages, the

wider ends of which form the grate surface apertures and the narrower ends of which form the restricted air inlets, the tapered passage serving the same purpose as the distribution chamber of my above mentioned prior application to space the restricted inlet away from the grate surface. Suitable dimensions for a passage formed by such tapered spaces would be 4. to 6 inches x at the outlet, and x /4 at the inlet, the passages being about 4 /2 inches long. The similarity of this construction with that described in the earlier specification above referred to will be better appreciated, perhaps, if the grate apertures were formed with projections to form a grill when the tapered passage could then be said to form a distribution chamber for the apertures of the grill. The disposition and construction of the apertures of the improved grate obviates the necessity of a grill or relatively small grate apertures, because the apertures are not required to be shaped so as to resist the entrance of the fuel. The rings of the grate are locked together by lugs 8 formed on their under-side and engaging the ends of notches t in the ring below. Other means such as lugs and bolts may be used for securing the rings of the grate together, and where the grate is' of large diameter, there may .be provided an intermediate support which for example may consist of brackets Supporting one of the In the water trough h is a plough, not shown, with which clinker in the trough is driven by the rotation of the trough. A steam jet or other form of saturator, not

shown, may be provided in the air inlet pipe, the steam assisting in the formation of producer gas and also acting to prevent the clinker reaching a temperature at which it will flow.

In operation, the downwardly increasing diameter of the combustion chamber allows for ex- 'pansion as the fuel descends and prevents it water-cooled lower section of the chamber wall,

which is at the zone of combustion, prevents clinker from sticking to the wall. The water cooling of the wall of the gas producer may be carried higher than herein illustrated if desired, as for example, by reason of special nature of the fuel to be used with which there is a greater possibility of the combustion rising from the grate surface. The scraper arm and cap are watercooled, both for their own preservation and to prevent the sticking of clinker. The cap also acts to break into the column of fuel and assists its downward fall on to the grate. In the particular producer above described, and particularly when burning garbage, the bell of the filling hopper has the advantage of providing a concave bed of fuel which is found to reduce the tendency for the formation of a wet centrol core.

Means of obtaining balanced draught, i. .e. of applying pressure so as to maintain the desired pressure at the gas outlet, may be used if desired.

Obviously, the invention is not limited to the particular details of construction of the example above described, for instance the scraper might be made to revolve and the grate be stationary or revolving also, at a different speed or in the opposite direction though the mechanical difiiculties in effecting this would obviously be greater.

Similarly it might be possible to dispense with the scraper by forming the rings of the grate of an arrangement of plates, like petals of a flower, the leading edges of which would be inclined so as to have a boring effect into the body of the fuel and would act also to drive the ash, clinker, etc., towards the periphery which at present is effected by the inclination from the radius of the leading edge of the scraper arms, The scraper is bound to have some effect of holding up the fuel and if it can be dispensed With some advantage will result but too much stress cannot be placed upon the importance of preventing the clinker from building up on the grate like an umbrella, under which the air can collect and issue without control at localized points of combustion.

Experiments which have been conducted with gas producers made with restrictive control in accordance with the aforesaid earlier specification, indicate that still further improved results are obtained by intensifying the restrictive control or relative proportions between the area of the air inlet and the area of the grate apertures which it supplies, where the air inlet area is reduced to about one-hundredth or less of the area of the grate apertures, and without materially reducing the through-put capacity of the gas producer. 7

What I claim is:-

1. A gas producer grate comprising annular conical overlapping plates of progressively decreasing diameter arranged upon one another in overlapping relation and provided between the overlapping parts with straight sided tapered ai-r passages, the sides of the air passages diverging outwardly towards the fuel bearing surface of the grate and their larger ends presenting a relatively large opening to the grate surface and their smaller ends being not greater than onesixth of the area of said large opening means for securing the plates together to form a conical grate, means for mounting the grate .for rotation as a unit, the outermost plate being provided with an apron, a water seal trough receiving the depending apron to form a water seal, means for supplying air to the center of the ,unit, and means for rotating the unit, the tapered passages 15c thereof having one of its sides substantially radial and the other side set back at an angle away from the direction of rotation of the unit.

2. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said elements in overlapped relation to form a conical grate, means for mounting said grate for rotation as a unit, said grate elements being provided with means forming a plurality of approximately radially disposed air passages the sides of which diverge outwardly toward the fuel bearing surface of said grate, said passages being located between the overlapped portions of the grate elements, and the cross sectional area of the inlet ends of said passages being materially less in area than the cross sectional area of the outlet ends of said passages.

3. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said grate elements in overlapped relation to form a conical grate, means for mounting said grate for rotation as a unit, said grate elements being provided between the overlapped portions thereof with means forming a plurality of straight sided air passages, the air passages being located between the overlapped portions of the grate elements and the sides of the passages diverging outwardly towards the fuel bearing surface of the grate, the cross sectional area of the inlet ends of said passages being not greater than one-sixth the cross sectional area of the outlet ends of said passages.

4. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said elements in overlapped relation to form a conical grate, means for mounting said grate for rotation as a unit, said grate elements being provided between the overlapped portions with means forming a plurality of tapering straight sided air passages, the sides of the air passages diverging outwardly towards the fuel bearing surface of the grate and each passage having one of its sides substantially radial and the other side set back at an angle away from the direction of rotation of the unit.

5. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said grate elements in overlapped relation to form a conical grate, means for mounting said grate for rotation as a unit, said grate elements being provided between the overlapped portions thereof with straight sided grooves formed in the lower faces of the grate elements and providing air passages having sides diverging outwardly towards the fuel bearing surface of the grate, the cross sectional area of the inlet ends of said passages being not greater than one-sixth the cross sectional area of the outlet ends of said passages.

6. A gas producer grate comprising a plurality of frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said grate elements in overlapped relation to form a conical grate, means for mounting said grate for rotation as a unit, said grate elements being provided with a plurality of projecting bosses between the overlapped portions thereof which hold the said grate elements in spaced relation, the sides of the bosses being straight and outwardly converged towards the fuel bearing surface of said grate, whereby a plurality of straight sided air passages are formed between the overlapped portions of said grate and the sides of said bosses, the sides of the air passages diverging outwardly and the cross sectional area of the inlet ends of said passages being not greater than one-sixth the cross sectional area of the outlet ends of said passages.

7. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said elements in overlapped relation to form a conical grate, said grate elements being provided with a plurality of projecting bosses between the overlapped portions thereof which hold the grate elements in spaced relation, the sides of the bosses being straight and outwardly converged towards the fuel bearing surface of said grate and forming a plurality of straight sided inwardly tapered air passages between the overlapped portions of the grate elements and the sides of the said bosses, the cross sectional area of the inlet ends of said passages being not greater than one-sixth the cross sectional area of the outlet ends of said passages.

8. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said elements in overlapped relation to form a conical grate, said grate ele ments being provided with a plurality of projecting bosses between the overlapped portions thereof which hold the grate elements in spaced relation, the sides of the bosses being straight and outwardly converged towards the fuel bearing surface of said grate and forming a plurality of straight sided inwardly tapered air passages between the overlapped portions of the grate elements and the sides of the said bosses, the cross sectional area of the inlet ends of said passages being not greater than one-sixth the cross sectional area of the outlet ends of said passages, said passages being approximately horizontal with their inlet ends located at a slightly higher elevation than their outlet ends.

9. A gas producer grate comprising a plurality of annular frusto-conical overlapping grate elements of successively decreasing diameter, means for securing said elements in overlapped relation to form a conical grate, means for mounting said grate for rotation as a unit, said grate elements being provided with a plurality of projecting bosses between the overlapped portions thereof which hold said grate elements in spaced relation, the sides of said bosses being straight and outwardly converged towards the fuel bearing surface of said grate to form a plurality of straight sided inwardly tapered air passages between said overlapped portions of the grate elements and the sides of the bosses, the cross sectional area of the inlet ends of said passages being not greater than one-sixth the cross sectional area of the outlet ends of said passages, means for rotating said grate, and a stationary water cooled scraper mounted over the grate and provided with a central conical cap completing the cone of the grate.

JOHN NORMAN WILLIAMS. 

